EVs are more susceptible to changes in battery performance based on the ambient temperature than petrol- and diesel-powered vehicles. Lithium batteries are positively affected by warmish weather, but negatively affected by extreme heat and cold. When the temperature drops below freezing or above 30C, a vehicle can lose 10-20% of its range, assuming all other factors remain the same (which they often don’t when it comes to the weather).
Hot weather means the batteries’ cooling systems have to be activated, and these draw power from the battery. You’ll also want to either use the air conditioning, or drive with the windows open (which makes the vehicle less aerodynamic).
The batteries need to be brought up to operating temperature to get the best performance due to the chemical reactions being slowed down in cold weather. You’ll likely want to use the heater. In a vehicle with an internal combustion engine, the engine’s warmth provides heat for the heater, but that’s not available in an EV, so any heat has to be generated using power from the batteries.
Standing water on the road increases the drag on the vehicle’s tyres meaning more power is required to keep the vehicle rolling. The deeper the water, the more the drag.
However, this might be mitigated to an extent by driving more slowly. EVs get their best economy at around 40km/h. If you would usually drive at 90km/h and you’re now driving at 75km/h, you are closer to the ideal 40km/h speed. This is because an electric vehicle has to push its way through the air, just like any vehicle, but the wind resistance increases exponentially with the speed (i.e. double the speed equals four times the wind resistance).
A headwind will tax the battery, although you will get a small boost when driving with a tailwind.
How do you improve the range of your vehicle?
The best option is to take our electric vehicle training course (click the image on the left). It explains all the driving techniques and other tips you can use to increase the range when driving.
During adverse weather, these four tips will help:
- Warm or cool your car while it’s still connected to the charger
- Keep your EV in a garage, where possible
- Try to pick times of the day when the temperature is as close to 20C as possible
- Use Eco mode.